Most botanical adulteration requires someone to decide to deceive. This one barely does. Two unrelated trees are called by the same name across India, one is protected and scarce while the other lines every second street, and the bark of both is brown and astringent. The substitution is almost built into the vocabulary.
Two Trees, One Name
| Genuine ashoka | False ashoka | |
|---|---|---|
| Species | Saraca asoca (Roxb.) Willd. | Polyalthia longifolia |
| Family | Fabaceae | Annonaceae |
| Habit | Small spreading evergreen | Tall narrow columnar tree |
| Where you see it | Groves, forest, temple sites | Roadsides, gardens, campuses |
| Availability | Scarce | Everywhere |
| Classical use | Ayurvedic women's health | None in this context |
These are not close relatives. They are in different families, and in the field nobody would confuse them — P. longifolia is the tall narrow tree used for avenue planting and windbreaks, quite unlike ashoka's spreading form.
The confusion is linguistic, not botanical, and it travels into the trade because plants are bought by name.
Why the Substitution Happens
Follow the economics and it is over-determined:
- Genuine S. asoca is slow-growing and assessed as threatened, with wild harvest under pressure and regulation;
- P. longifolia is planted by the million as an ornamental, is fast-growing, and is routinely pruned and felled in ordinary municipal maintenance;
- Bark from the second is therefore available at a fraction of the cost — often as a by-product of work that was happening anyway;
- And it is locally called ashoka, so a collector supplying it may not consider themselves to be substituting anything.
That last point matters for how you defend against it. This is not principally a story about bad actors — it is a story about a vocabulary collision meeting a price differential. No amount of supplier goodwill closes it. Only a test does.
Once It Is Bark, You Cannot See It
The trees are unmistakable standing up. Dried, cut and milled, that advantage disappears:
- Both yield brown, astringent bark;
- Both are tannin-bearing;
- Colour and odour overlap enough to be unhelpful;
- Powder removes what remains.
Macroscopic and microscopic examination of intact bark by a trained analyst can distinguish them, which is worth doing at raw-material intake. But by the time material arrives at an extractor as milled bark — let alone as extract — chromatography is the practical answer.
Why the Tannin Assay Fails
Almost every ashoka specification in the market is written on tannins.
Tannins are among the most widespread constituents in bark generally. Both species carry them. A 5% tannin specification is met by genuine ashoka, by false ashoka, and by a range of other barks besides.
This is the same structural failure that appears wherever a class assay is asked to do an identity job — the tannin figure on arjuna, the bitter-principles figure on giloy. The assay is honest; it is simply answering a different question.
What Detects It
The flavan-3-ol profile by HPLC, principally:
- (−)-Epicatechin — the most useful single marker for S. asoca bark;
- Catechin — and the relationship between the two;
- Procyanidins — the condensed tannin pattern.
Read as a pattern against authenticated S. asoca reference material, this separates the two species in a way no single-number assay can. And as always, the certificate should name P. longifolia as excluded rather than merely naming the wanted species — naming what you tested against is what makes the claim verifiable.
Where to Test
- Raw material intake — where intact bark can still be examined macroscopically and microscopically, and where rejection is cheapest;
- Finished extract — because that is what ships, and because blending can happen after intake.
Verification at supplier qualification only does not control ongoing supply. Require it per batch.
The Other Routes, Briefly
Species is the dominant issue but not the only one:
- Wood and inner stem milled with bark — caught by the stem-bark declaration and acid-insoluble ash;
- Other tannin-rich barks blended in — caught by the catechin profile;
- Milled bark powder as extract — caught by the tannin assay and by appearance.
Three Questions for a Supplier
- "What binomial is on your certificate?" — and is it S. asoca rather than "S. indica"?
- "Do you exclude Polyalthia longifolia, and is that stated?"
- "Can you provide a catechin and epicatechin profile against reference material?"
A supplier controlling this material answers all three without pause. Talk to us about ashoka or read the buyer's guide.
Source Species-Confirmed Ashoka Extract from India
Saraca asoca stem bark extract · Polyalthia longifolia excluded by HPLC · catechin markers reported · source declared per batch · CoA-backed · samples for qualified buyers